Gas blast circuit breaker



Filed May 28, 1941 K 4 aw H. THOMMEN ET AL GAS BLAST CIRCUIT BREAKERDec. 5, 1944.

Patented Dec. 5, 1944 UNITED STATES PATENT OFFICE GAS BLAST CIRCUITBREAKER land Application May 28, 1941, Serial No. 395,692 In SwitzerlandJune 10, 1940 6 Claims.

This invention relates to electrical switches of the gas blast type inwhich the arc extinction chamber and the exhaust chamber which iscombined with the former, together with the contacts, are mounted on acompressed gas container by means of an intermediate-supportinginsulator which serves to conduct the supply of compressed gas to thecontacts. The blow valve is located at the end of the arcing chamberfacing the supporting insulator and preferably in the coupling betweenthis latter and the arcing chamber. When the switching device comprisesa gas blast circuit breaker and a voltage disconnecting switch arrangedin series the control mechanisms for the blow valve and the voltagedisconnecting switch are located inside the coupling. These controlmechanisms, being at the energized side of the supporting insulator, canbe actuated by means of insulator rods from the grounded side of theswitching device.

The object of the invention is to improve switching devices of this kindstill further by constructing the insulator rod gear so that in additionto actuating the control mechanism it also indicates the position of thevoltage isolating switch.

The invention will be more particularly described with reference to theaccompanying drawing in which the figure shows a diagrammaticrepresentation in partial section of a switching device embodying theinvention, all elements not essential for an understanding of theinvention having been omitted.

In the drawing a is the compressed gas container which may be madeportable. Mounted on this container is the supporting insulator b whichsupports the switch chamber c. This switch chamber can contain one ormore power rupturing points arranged in series for interrupting thecircuit. In the constructional example illustrated in the drawing it isassumed that there is a plurality of rupturing points, each of which islocated in a special switch chamber comprising an insulator element withmetallic end parts which are held together by tie rods. These switchchambers are provided with exhaust outlets for the exhaust gases, theseoutlets being fitted with closing elements if necessary. Inside thecoupling h between switch chamber 0 and supporting insulator b is theblow valve 1 which has a control piston k. The control valve m for theblow valve 1' is actuated by the transmission rod 12 of the insulatorrod system that is located inside the insulator b, this system alsoincluding a cam m and a pivoted lever m. The rod system is actuated byrotating the shaft m by hand, pneumatically or electro-pneumaticallythrough the mid-position to either of the end positions I or II. Thevoltage disconnecting switch is provided with a pivoted blade. Thedisconnecting switch p is opened and closed by means of the controlpistons t1, t2. The piston ii is in communication with the space behindthe blow valve through the conduit in, and the piston t2 is connectedwith the space below the blow valve through the conduit uz and thechange-over valve v, thus being in direct communication with thecompressed gas container. The change-over valve 1) is actuated from thedisconnecting switch p by means of link rod 101, lever um and springsan, are, these latter being located on the insulator rod n and alsoserving to guide the rod in its end positions.

If the circuit breaker is to be opened the shaft n1 must be brought intothe mid-position, whereupon the cam m on the insulator rod n is at firstonly lifted to such an extent that the end of lever n3 lies on thehighest point of the cam. The control valve m is thus opened andcompressed gas flows from container a through tube In to the rear sideof the control piston is of the blow valve 1'. The blow valve 2' thenopens and compressed gas fiows to the circuit breaking points in switchchamber 0, opening the arcing contacts and subjecting the arc to a blastof gas. Due to the opening movement of the blow valve communication isestablished with conduit in and compressed can pass to control pistonii. The conduit in is equipped with some form of throttling element inorder to delay the opening of the voltage disconnecting switch 10. Whenswitch p moves into the "open position II change-over valve 11 isactuated by means of link rod 'LDl and lever 102, thus interrupting theconnection between the control valve m and the space behind the piston kof the blow valve i. The arrangement of this control mechanism is suchthat before valve '11 is displaced by lever wz and spring :21 the cam inand the rod n reach the top end position so that the control valve m isclosed again. Before change-over valve v closes. the space above thecontrol piston k is exhausted so that the blow valve is closed by thegas pressure, this action being supported if necessary by a spring notshown in the drawing.

In order to close the voltage disconnecting switch blade the insulatorrod mechanism must be brought back into the mid-position from the endposition II. During this operation the cam n2 moves downwards into aposition where the end of the lever m first rests on the highest point1: being in the upper position. With the movemerit of the disconnectingswitch to the closed position the change-over valve 11 is opened firstand then the cam n2 is brought into the lower end position I. The valvem can close again. Upon this indication regarding the position of thevoltage disconnecting switch blade the insulator rod is moved stillfurther in dependence on the movement of the disconnecting switch, afterthe switching operation has been executed. The change-over valve 2:controlled by the disconnecting switch prepares the circuit breaker forthe next operation in the reverse order after the circuit has beeninterrupted and reclosed. The control valve m of the blow valve isactuated in such a manner that during the execution of the controloperations it is closed in the end positions,

but open in the mid-position.

In the embodiment of the invention shown in the drawing one insulatorrod serves to control the blow valve and the voltage disconnectingswitch and also to indicate the position of the disconnecting switch.This rod is subjected to compressive and tensile stresses. In order torelieve the rod from compressive stress it is for instance possible toprovide a spring which continuously pulls the rod upwards. It is ofcourse also possible to use more than one rod and to arrange so that allrods are only subjected to tension. Separate rods for the control andthe position indication signal can be provided. The

mechanism can also be arranged in such a manner that the change-overvalve is first actuated after the control valve for the blow valve hasbeen closed. If the circuit breaker has a device for reclosing the powercircuit breaker with the voltage disconnecting switch closed, it isexpedient to employ an insulator rod mechanism which closes and opensthe compressed gas conduit to the piston which opens the disconnectingswitch.

We claim:

1. In a switch, a gas blast circuit breaker mounted on a supportinginsulator, a disconnect switch in series with the circuit breaker, meansincluding a control valve positioned on the energized side of thesupporting insulator for operating said circuit breaker, cylinder andpiston means for operating said disconnect switch between open andclosed positions, a source of pressure gas, an insulator rod systemoperable from the grounded side of said supporting insulator foractuating said control valve and admitting pressure gas from said sourceto said cylinder and piston means, and means including a changeovervalve operable by said cylinder and piston means as it actuates saiddisconnect switch to an end position to establish pressure-gasconnections to said cylinder and piston means for energization thereofto actuate the disconnect switch to its alternative end position uponthe next admission of pressure gas to said cylinder and piston means byoperation of said insulatorrod system.

2. In a switch, the invention as recited in claim 1, wherein saidinsulator rod system is adjustable between two end positions to admitpressure gas to said cylinder and piston means to open or alternativelyto close said disconnect switch, and said insulator rod system includesmeans operable at an intermediate position of adjustment thereof to opensaid control valve to operate said circuit breaker to open position.

3. In a switch comprising a gas blast circuit breaker mounted on asupporting insulator, means connecting said circuit breaker with asource of compressed gas including a piston-actuated blow valve foradmitting a blast of compressed gas to the circuit breaker, a disconnectswitch in series with the circuit breaker, means including apressure-responsive piston for opening said disconnect switch and apressure-responsive piston for closing said disconnect switch, controlmeans positioned on the energized side of the supporting insulatorcomprising a control valve for admitting compressed gas to the blowvalve piston to open the blow valve, means actuated by the openingmovement of the blow valve for admitting compressed gas to the firstpiston to open the disconnect switch, means actuated by the closingmovement of the disconnect switch to shut off the supply of compressedgas to the blow valve piston and to admit compressed gas to the secondpiston to close the disconnect switch, and means for actuating saidcontrol valve comprising an insulator rod system operable from thegrounded side of the supporting insulator.

4. In a switch system, the combination with a gas blast circuit breakermounted on a hollow supporting insulator, said circuit breaker includingmeans operable by compressed gas to actuate the circuit breaker, and adisconnect switch in series with the circuit breaker, of meansresponsive to compressed gas to actuate the disconnect switch, valvemeans positioned at the energized side of the supporting insulator forcontrolling the flow of compressed gas to the actuating means of saidcircuit breaker and then to the actuating means of said disconnectswitch, control means comprising an insulator rod system operable fromthe grounded side of said supporting insulator to operate said valvemeans to admit compressed gas to the actuating means of the circuitbreaker and disconnect switch, and means responsive to movement of thedisconnect switch as it approaches either full-open or fullclosedposition to operate said valve means to interrupt flow of compressed gasto the actuating means of said circuit breaker.

5. In a switch system, the invention as recited in claim 4, wherein saidinsulator rod system includes a longitudinally movable insulator rodextending through said supporting insulator from the grounded to theenergized side thereof.

6. In a switch system, the invention as recited in claim 4, wherein saidinsulator rod system in-- cludes a single insulator rod extendingthrough said supporting insulator from the grounded to the energizedside thereof, and means for moving said rod longitudinally between twoend positions.

HANS THOMMEN. ALFRED HALM.

GOTTFRIED BRiiHLMANN.

